Figure 9.

The PVC SNARE VTI11 Is Essential for TuMV Infection.

(A) Wild-type (wt) or itt3 plants under UV light 25 d after agroinoculation with TuMV/6K₂:GFP (left panel). Time course of TuMV systemic infection of wild-type Arabidopsis plants (circled) and itt3 loss-of-function mutant plants (diamonds) after pCambiaTuMV/6K₂:GFP agroinoculation (right panel). Infection was scored by appearance of systemic GFP fluorescence.

(B) Wild-type or itt3 plants under UV light 25 d after agroinoculation with PlAMV:GFP (left panel). Total proteins extracts from TuMV/6K₂:GFP- or PlAMV:GFP-inoculated wild-type or itt3 rosettes were analyzed by immunoblot with anti-GFP antibodies (right panel).

(C) Time course of TuMV intercellular movement after agroinoculation of pCambiaTuMV/6K₂:mCherry//GFP-HDEL into wild-type Arabidopsis plants. Expression of GFP and mCherry fusions was acquired at 3, 4, and 5 dpi by confocal microscopy (upper panels). The graph below shows viral replication as evaluated by RT-qPCR from Arabidopsis wild-type and itt3 leaves that were agroinfiltrated with pCambia (Mock), pCambiaTuMV^VNN (VNN), or pCambiaTuMV (TuMV) at 4 dpi. Statistical differences between samples were determined by t test analyses (*P < 0.05). Error bars show the sd calculated from values obtained in the three biological replicates.

(D) CFDA dye transport in wild-type Arabidopsis and itt3 plants observed by confocal microscopy of inoculated rosette leaves and of systemically infected leaves 6 and 24 h postinoculation. Upper panels, fluorescence; lower panels, bright-field images.

Three independent biological replicates were performed for (A) to (C) and two for (D). Bars = 10 mm in (A) and (B), 20 μm in (C), and 1 mm in (D).